clk: renesas: Pull Gen3 specific bits into separate header

Extract the macros specific to Gen3 clock into a separate header.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/drivers/clk/renesas/r8a7796-cpg-mssr.c b/drivers/clk/renesas/r8a7796-cpg-mssr.c
index 016ab3d..80e07da 100644
--- a/drivers/clk/renesas/r8a7796-cpg-mssr.c
+++ b/drivers/clk/renesas/r8a7796-cpg-mssr.c
@@ -18,6 +18,7 @@
 #include <dt-bindings/clock/r8a7796-cpg-mssr.h>
 
 #include "renesas-cpg-mssr.h"
+#include "rcar-gen3-cpg.h"
 
 enum clk_ids {
 	/* Core Clock Outputs exported to DT */